Perhaps you should try some spelling variations:
cong thanh » dong thanh, cong trinh, cong tan
hieu lang » chieu sang, hieu quang, nhieu tang
canh sinh » canh tinh, canh binh, tinh sinh
cong dan » cong san, cong tan, huong dan
chan cau » phan cau, can cau, chinh cau
ho hieu » ho chieu, hoi hieu, nho hieu
sinh va » sinh vat, tinh va, dinh van

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ho hieu lang - canh sinh va nhung ((cong dan) or (cong thanh)) chan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho hieu lang - canh sinh va nhung ((cong dan) OR (cong thanh)) chan cau.
• Adding a wildcard symbol may retrieve word variants: ho hieu lang - canh sinh va nhung ((cong dan) or (cong thanh)) chan cau*.